Friction draft-gear.



J. F. OCONNOR.

PBIOTION DRAFT GEAR.

APPLIOATION FILED DBO. z8, 1910.

' Patented Fb. 13, 1912.

2 SHEETS-SHEET 1.

hisArToRNErs J. E'. OGONNOR. PBIGTION DRAFT GEAR.

APPLIOATION FILED DB0. 2e, 1919.`

Patented Feb. 13, 1912.

2 SHEETS-SHEET 2.

/visAjromv-Exs' y tric JOHN F. OCONNOR, OF`CHICAGO, ILLINOIS, ASSIGNORTO WILLIAM H. MINER, 0F

CHICAGO, ILLINOIS. i

FRICTION DRAFT-GEAR.

Loiaeeo.

Specification of Letters Patent.

Patented Feb. is, i912;

Application filed December 28, 1916. y Serial No. 599,754.

To all whom t may concern.'

lie it known that I, JoirN F. OCONNOR, a citizen of the United States,residing in Chicago, in the county of Cook and State of Illinois, haveinvented a new and useful linproveinent in Friction Draft-Gears, ofwhich the following is a specification.

My invention relates to improvements in friction draft gear or draftrigging for railivay cars, and more particularly to friction draftrigging of the kind employing a friction shell oi cylinder, frictionslices' and Wedge Within the cylinder.

Heretofore in the practical operation 4of friction draft rigging of thekind to which my invention relates, diiiiculty is sonictiniesexperienced froni lack of `iiiiifoiinity in thc action of the frictionmechanism under different conditions of the interengaging frictionfaces,incident to rust and other causes affecting the coefficient offriction.

The object of niy invention' is to provide a friction draft gear of astrong, simple, eflicient and durable construction, in which .thefrictional action of the shell and shoes will .be substantially uniforinand their interengaging friction faces maintain a substantially unifornicoefficient of friction under all conditions of practical use, in whichalso the requisite frictional resistance may be developed without.appreciable wear of either the. friction slices or shell.

My invention consists in the nicans which I have discovered forpractically accomplishing this important and useful result, and thepractical operation of which I have thoroughly demonstrated `both byexperiinent and actual use; the saine consisting essentially in thecombination With friction shoes of steel or cast steel, and having casehardened, smooth, polished friction faces, of a inalleable iron frictionshell having an interior friction face layer or skin of relativelydense, line grained and brittle nietal, and provided with an outeroxidized coating which cornes directly in contact with the smooth,polished, hardened steel friction faces of the friction shoes. This llind produces a high degree of frictional resistance Without appreciableWear of either the friction shell or shoes, and the coetlicicnt offriction of the interengaging friction faces remains substantially thesaine under vary- `ing conditions of practical use.

The friction shoes are preferably niade of cast steel, the externalfriction faces being i'st finished or trued and ground to accurate shapeand polished, and then case hardened to produce a friction face layer toa depth of a sixteenth of an inch or such Inatter of extremely hardsteel.

To provide the friction shell or'cylinder With the required relativelydense, hard, fine grained and brittle friction face layer, and with apermanent exterior oxidized coating, I subject the hard, Whit-e ironcasting of which the friction shell its made, to an annealing operationin a iniitlled, sealed or closed annealing` oven Without any packingmaterial of any kind enveloping the White iron casting either interiorlyor exteriorly, so that the annealing operation itself Will, whilethoroughly annealing, softening and toughening the interior portion ofthe White iron casting, leave the saine With an external layer or skinboth upon its inner friction face and its Ioutside, which is relativelydense, hard, comparatively brittle and line grained or fi'iable, andadapted to producen high degree of frictional resistance When sli-dingunder heavy pressure against a hardened steel friction shoe, theannealing operation further operating to provide this hardened, finegrained, friablle, dense layer or skin with a thoroughly oxidizedcoating, which oXidized coating I i'ind in practical operation, incombination with the` hardened steel, sinooth, polished friction slices,perinanently remains on the interior face of the friction shell and hasthe result of preventing the inner friction face of the shell frombecoming bright, and the further result of causing the frictionalresistance to Vreniain substantially constant under all varyingconditions of use. After the friction. shell has thus been annealed andprovided on its interior friction face with a relatively hard, denselayer provided with an oxidized coating` in order to bring the interiorfriction face to ay true, cylindrical shape or to the` forni required toproperly fit the external friction faces of the friction slices, Withoutremoving or destroying its dense, in'iier friction .face layer or skin,I subject the friction shell, when it is necessary or out ofy truefoi-in, to an internal snaping pressure from an expanding, shaping ortruing device which is inserted Within the friction'shell and expandedto bring its interior to a true, cylindrical form or to suchrother formas cfa tit)

may be required to properly tit the friction shoes. l

ln the drawing, Figure 1 is a plan view, partly in central horizontalsection of a fric tion draft rigging embodying my invention. Fig. :2 isa side elevatlou, partly in section on line 2 2 of Fig. 1. Fig. 8 is avertical, transverse section taken on the line 3-3 of Fig. 2, andlooking in the direction of the arrows. Fig. t is a transverse,verticalsection, upon an enlarged scale, of the friction shell andshoes, and Fig. 5 is an enlarged, partial, longitudinal section of thefriction shell and shoes. I

ln the drawing, 1 represents the center sills or draft members of thecar frame to which the draft rigging is applied, 2 the front end sill, 3the draw-bar, et the draft yoke, 5, 6 front and rear followers, 7, 8stop members secured to the center sills and against which the followersabut. rlivin springs 9, 10, arranged side .by side, are preferablyemployed, the saine having smaller springs 11, 12 nested Wit-hin them.'.lhe springs are inclosed in a spring cage 13s with which the rearfollower may be made integr-ai. The springs bear at their `front endagainst a twin spring cap or seat member 14 which has a central boss orbearing 15 for engagement -tvith the rear ends of the friction shoes 16Which' tit Within the friction shell orcylinder 17, and are outwardlyspread by thewedge 18 through the interposed anti-friction rollers 19.

The friction shoes 16 are preferably three in number, as indicated inthe drawing, and thejsanie are preferably of cast steel, and eachprovided with a smooth, polished elifternal friction face 20 of hardenedsteel forned on the integral, external case-har dcned `layer 21 of thesteel shoe. Each of the friction shoes also has an inclined Wedge 22formed in a case-hardened external layer Q3 of the steel shoe forengagement with the anti-friction roller 19. The Wedge i8 has a.plurality of Wedge faces 24, formed in case-hardened layers 25 of theWedge for engagement with the anti-friction roller.

The friction shell 17 is of malleable iron and has an interior or bodyportion 26 of relatively soft, strong, tough, tenacious, long fiberedmetal, and an external inner friction face layeror skin 27 of i.. dense,brittle or friable and' 'line short tlbered metal., provided withpermanently nidi/red exterior or coating 28 constituting the internalfriction face of the cylinder, `whichis in sliding frictionalengagementvt'ith the smooth, polished, case hardened friction faces ofthe friction slices.

in my invention, the malleable iron friction shell has an integralfriction face layer or skin of relatively hard. dense, brit Etle` orfriable and short iibered metal with a permanently oxidized coating orexterior ,tively hard,

portieri constituting the friction face of the shell, and as thefriction shoes have.smooth, polished, case hardened steel frictionfaces, a relatively high degree of frictional re sistance is developedby the sliding of the shoes on the shell under heavy pressure. And Ifind in p `actical use that the coctli cient of friction remainssubstantially constant under varying conditions of practical frictionshoes or friction shell, and the' draft rigging is entirely free fromall tenddency of the inter-engaging friction` elc ments. to out orunduly Wear. As in my invention, the inner friction face layer or skinof the friction shell at the outermost portion thereof becomes highlyoxidized to an appreciable depth and is thus rendered refractory andheat resisting in character, and also of a character to elfectuallyresist any tendency to Weld, fuse or nietallically unite with the brightmetal friction face of the steel slices when sliding under enern mouslyheavy pressure, the fricticnal resistance is produced vvithout anyappreciable tendency of the intorengaging friction faces to cut or Wear.The oxidized refractory outer portion of the friction face layer or skinof the friction shell serves to prevent the interengaging faces of theshell and shoes from approaching a condition or state in which cutting,grooving, or excessive Wear can take place, While at the same timeproducing a high. degree of frictional re sistance.

l claim 1. lin a friction draft rigging, the coinbination of frictionshoes having hardened steel fric-tion faces, of a malleable ironfriction shell having an integral friction face layer or skin ofrelatively hard, dense, brit tle metal, substantially as specified.

2. In a friction draft rigging, the combii nation of friction shoeshaving hardened steel friction faces, of a malleable iron fricl tionshell having ai integral friction face layer or skin of relatively hard,dense, brit-- tle metal, with the outermost portion oxidized,substantially as specitied.

3. ln a friction draft rigging, the combination with cast steel frictionshoes having hardened and polished friction faces and hardened rollerbearing Wedge faces, a wedge having hard roller bearing Wedge faices,hard steel anti-friction rollers inter posed between thewedge andfriction shoes.'

los

norms-'so and a malleable iron friction shell haring a relativelyv hardand dense friction face layer iii sliding frictional engagement with thehard smooth, polished friction faces of the friction shoes,substantially as speciied.

n a friction draft rigging, 'the combination with east steel frictionslices having hardened friction faces and hardened roller Gearing Wedgefaces, a Wedge having hard roller bearing Wedge faces, hard steel anti-"^tion rollers interposed between the wedge and friction slices7 and amalleable iron friction shell having a relatively hard and densefriction face layer in sliding frictional engageinent with the hardsmooth, polished friction faces of .the friction shoes, said frictionface layer or skin of the malleable iron friction shell having; itsoutermost portion oxidized, substantially as specified.

JOHN F. GCONNOR. Writnesses:

EDMUND Aococii, PEARL ABRAMS.

